Insulin Dose Calculator
Calculate basal and bolus insulin doses based on weight, carb ratio, correction factor, and current glucose levels.
About this calculator
This calculator splits insulin dosing into two separate questions: how much background (basal) insulin is needed regardless of food, and how much bolus insulin is needed for the meal in front of you right now. If a known Total Daily Dose isn't entered, it defaults to a starting estimate of 0.5 units per kilogram of body weight per day -- this is the rough full-replacement figure for type 1 diabetes given in the American Diabetes Association's annually-updated Standards of Care in Diabetes, not a type 2 starting dose. Type 2 basal insulin is typically started far lower, around 10 units per day or 0.1-0.2 units/kg/day, per the same ADA Standards of Care; using the 0.5 units/kg figure for a type 2 patient can overstate a reasonable starting dose several-fold. Either way this is a beginning point for clinical titration, not a fixed prescription -- real insulin needs vary with diabetes type, insulin resistance, activity level, and illness. From that TDD, this calculator applies the standard 50/50 split to report the basal portion: half of TDD covers basal (background) needs, with the remainder available for meal and correction dosing through the rest of the day.
The meal bolus itself is carbohydrates to be eaten divided by the insulin-to-carb ratio (ICR), while the correction dose is the gap between current and target glucose divided by the correction factor (ISF), floored at zero so a below-target reading never produces a negative recommendation. Total meal bolus adds the two together. This calculator assumes the ICR and ISF entered are for rapid-acting insulin, the type used for meal and correction dosing in modern regimens. Unlike the basal split, ICR and ISF are entered directly here rather than derived from TDD -- if you don't already know your ratios from a diabetes care team, the insulin pump calculator derives starting ICR/ISF estimates from TDD using published rules of thumb.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
This tool estimates a starting point only and is not a validated clinical decision-support system. It does not account for every patient-specific factor (organ function, drug interactions, allergies, comorbidities, or current clinical status). Any dose, rate, or setting must be independently verified by the treating clinician and pharmacist or respiratory therapist against current institutional protocols, product labeling, and the patient's full clinical picture before being administered or applied.
Inputs
Results
Basal Dose (50% TDD)
17.5 units
Meal Bolus Dose
4.5 units
Total Meal Bolus
6.1 units
Figures current as of 2026. Source: American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2026. Diabetes Care. 2026;49(Suppl 1):S183-S215.
How to Use This Calculator
- Enter your Body Weight in kg and your known Total Daily Dose (TDD) in units — or leave TDD at 0 to auto-estimate at 0.5 units/kg.
- Enter your Insulin-to-Carb Ratio (ICR in g/unit) — for example, 10 means 1 unit covers 10 g of carbs.
- Enter your Correction Factor (ISF) in mg/dL per unit and your Current Blood Glucose and Target Blood Glucose in mg/dL.
- Enter Carbs to Eat for this meal in grams.
- Review the Basal Dose (50% TDD), Meal Bolus Dose (carbs ÷ ICR), Correction Dose, and Total Meal Bolus — always confirm doses with your diabetes care team before adjusting.
How the result changes with Body Weight
| Body Weight | Basal Dose (50% TDD) | Meal Bolus Dose | Total Meal Bolus |
|---|---|---|---|
| 35 | 8.8 units | 4.5 units | 6.1 units |
| 53 | 13.3 units | 4.5 units | 6.1 units |
| 105 | 26.3 units | 4.5 units | 6.1 units |
| 175 | 43.8 units | 4.5 units | 6.1 units |
What each input means
- Body Weight
- Your body weight in kilograms. Used to estimate TDD if not provided.
- Total Daily Dose (TDD)
- Known total daily insulin dose in units. Leave at 0 to auto-calculate from weight (0.5 units/kg).
- Carb Ratio (ICR)
- Insulin-to-carb ratio: grams of carbs covered by 1 unit of insulin.
- Correction Factor (ISF)
- Insulin sensitivity factor: how much 1 unit of insulin lowers blood glucose (mg/dL). Clinically typical values run roughly 10-100+.
- Current Blood Glucose
- Your current blood glucose reading in mg/dL.
- Target Blood Glucose
- Your target blood glucose level in mg/dL.
- Carbs to Eat
- Grams of carbohydrates you plan to eat this meal.
What each result means
- Basal Dose (50% TDD)
- Background insulin dose, independent of food: 50% of Total Daily Dose.
- Meal Bolus Dose
- Insulin to cover the meal's carbohydrates: Carbs to Eat divided by the Carb Ratio (ICR).
- Correction Dose
- Additional insulin to bring an above-target glucose reading down to target: (Current − Target Glucose) divided by the Correction Factor (ISF), floored at 0.
- Total Meal Bolus
- Meal Bolus Dose plus Correction Dose — the full bolus to give with this meal.
- Total Daily Dose Used
- The TDD actually used in the calculation: your entered Total Daily Dose, or the weight-based estimate (0.5 units/kg) if TDD was left at 0.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersBody Weight = 70, Total Daily Dose (TDD) = 0, Carb Ratio (ICR) = 10, Correction Factor (ISF) = 50 = 7 input(s) provided
- Calculate Basal DoseBasal Dose17.5 = 17.5
- Calculate Meal Bolus DoseMeal Bolus Dose4.5 = 4.5
- Calculate Total Meal BolusTotal Meal Bolus6.1 = 6.1
- Calculate Correction DoseCorrection Dose1.6 = 1.6
Figures and sources
- ADA Standards of Care in Diabetes — insulin initiation dosing (2026) — American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2026. Diabetes Care. 2026;49(Suppl 1):S183-S215.
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Is the 0.5 units/kg/day starting dose right for type 2 diabetes?
No -- 0.5 units/kg/day is the ADA's rough full-replacement figure for type 1 diabetes, used here only as the fallback when Total Daily Dose is left at 0. Type 2 basal insulin initiation is typically much lower, around 10 units per day or 0.1-0.2 units/kg/day per the ADA Standards of Care. If you have type 2 diabetes, enter a known Total Daily Dose from your care team rather than relying on this calculator's fallback estimate.
What happens if I leave Total Daily Dose at zero?
The calculator falls back to a weight-based estimate of 0.5 units per kilogram of body weight per day -- the type 1 full-replacement figure, not a personalized number and not appropriate for type 2 basal initiation (see the question above). Actual total daily insulin need can run higher or lower depending on diabetes type, insulin resistance, activity level, and other factors your care team would weigh in on.
Where do the Insulin-to-Carb Ratio and Correction Factor come from if I don't know mine?
This calculator takes ICR and Correction Factor (ISF) as direct inputs rather than deriving them from Total Daily Dose. If you don't already have these numbers from a diabetes care team, the insulin pump calculator estimates starting ICR and ISF values from TDD using the published 500 and 1800 rules of thumb -- treat those as a starting point to be confirmed clinically, the same as the weight-based TDD fallback here.
Why is the correction dose always zero when current glucose is at or below target?
This calculator floors the correction dose at zero rather than producing a negative number. A current glucose at or below target means no additional correction insulin is needed for that factor -- it does not mean insulin should be subtracted from the meal bolus, which is calculated independently. Note also that this calculator does not warn on a low current-glucose reading itself (below roughly 70 mg/dL) -- a pre-meal low should be treated first, separately from bolus dosing.
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